Debian GNU/Linux 7 syzkaller ttyS0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 20.234882] ================================================================== [ 20.237431] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 executing program [ 20.238056] Read of size 8 at addr ffff880039a6d880 by task blkid/3471 [ 20.238889] [ 20.239057] CPU: 3 PID: 3471 Comm: blkid Not tainted 4.14.0-rc5-next-20171018+ #8 executing program executing program executing program [ 20.239825] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 20.241887] Call Trace: [ 20.242080] dump_stack+0x194/0x257 [ 20.242333] ? arch_local_irq_restore+0x53/0x53 [ 20.242671] ? show_regs_print_info+0x65/0x65 [ 20.242998] ? kfree_const+0x31/0x40 [ 20.243260] ? disk_unblock_events+0x51/0x60 [ 20.243573] print_address_description+0x73/0x250 [ 20.243905] ? disk_unblock_events+0x51/0x60 [ 20.244212] kasan_report+0x25b/0x340 [ 20.244487] __asan_report_load8_noabort+0x14/0x20 [ 20.244827] disk_unblock_events+0x51/0x60 executing program executing program executing program executing program executing program executing program executing program [ 20.245106] __blkdev_get+0x78d/0xf90 [ 20.247628] ? __blkdev_put+0x7c0/0x7c0 [ 20.248096] blkdev_get+0x3a1/0xad0 executing program [ 20.248555] ? do_raw_spin_trylock+0x190/0x190 [ 20.249249] ? bd_link_disk_holder+0x8b0/0x8b0 executing program [ 20.249605] ? __fsnotify_parent+0xb4/0x3a0 [ 20.250117] ? errseq_sample+0xee/0x140 [ 20.250531] ? _copy_to_user+0xc0/0xc0 [ 20.250964] ? _raw_spin_unlock+0x22/0x30 [ 20.251363] blkdev_open+0x1c9/0x250 executing program executing program executing program [ 20.251708] ? security_file_open+0x89/0x190 [ 20.253490] do_dentry_open+0x664/0xd40 [ 20.253847] ? security_inode_permission+0xbb/0xf0 executing program [ 20.254258] ? bd_acquire+0x2c0/0x2c0 executing program executing program [ 20.254673] vfs_open+0x107/0x220 [ 20.257814] path_openat+0x1151/0x3520 [ 20.258172] ? path_lookupat+0xba0/0xba0 [ 20.258508] ? lock_downgrade+0x990/0x990 [ 20.258824] ? do_sys_open+0x2e7/0x6d0 [ 20.259130] ? do_raw_spin_trylock+0x190/0x190 [ 20.259487] ? find_held_lock+0x35/0x1d0 [ 20.259789] ? __lock_is_held+0xb6/0x140 [ 20.260097] ? _find_next_bit+0xee/0x120 [ 20.260406] ? _raw_spin_unlock+0x22/0x30 [ 20.260849] ? __alloc_fd+0x29b/0x750 executing program executing program [ 20.261313] do_filp_open+0x25b/0x3b0 [ 20.262255] ? may_open_dev+0xe0/0xe0 [ 20.262646] ? mpi_resize+0x200/0x200 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 20.262996] ? get_unused_fd_flags+0x121/0x190 [ 20.269693] ? getname_flags+0x256/0x580 [ 20.270108] do_sys_open+0x502/0x6d0 [ 20.270474] ? do_sys_open+0x502/0x6d0 [ 20.270856] ? filp_open+0x70/0x70 [ 20.271170] ? entry_SYSCALL_64_fastpath+0x5/0xbe executing program executing program executing program [ 20.271592] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 20.273709] SyS_open+0x2d/0x40 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 20.274024] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 20.283346] RIP: 0033:0x7f99b68cd120 executing program executing program [ 20.283682] RSP: 002b:00007ffe876f0068 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 executing program [ 20.284836] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f99b68cd120 [ 20.285753] RDX: 00007ffe876f1f45 RSI: 0000000000000000 RDI: 00007ffe876f1f45 executing program [ 20.286563] RBP: 0000000000000082 R08: 0000000000000078 R09: 0000000000000000 executing program [ 20.287417] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000013fb030 [ 20.288265] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 [ 20.289119] executing program executing program [ 20.289344] Allocated by task 3464: [ 20.291517] save_stack+0x43/0xd0 executing program [ 20.291767] kasan_kmalloc+0xad/0xe0 executing program [ 20.292236] kmem_cache_alloc_node_trace+0x150/0x750 [ 20.292838] alloc_disk_node+0xb4/0x4e0 [ 20.293339] alloc_disk+0x18/0x20 [ 20.293731] loop_add+0x45c/0xa50 executing program [ 20.294105] loop_probe+0x16d/0x1a0 [ 20.294572] kobj_lookup+0x2ac/0x410 [ 20.294948] get_gendisk+0x37/0x230 [ 20.295312] blkdev_get+0x12d/0xad0 executing program [ 20.295665] blkdev_open+0x1c9/0x250 [ 20.296170] do_dentry_open+0x664/0xd40 [ 20.296631] vfs_open+0x107/0x220 [ 20.296973] path_openat+0x1151/0x3520 executing program [ 20.297373] do_filp_open+0x25b/0x3b0 executing program executing program executing program [ 20.297823] do_sys_open+0x502/0x6d0 executing program executing program executing program executing program executing program [ 20.305236] SyS_open+0x2d/0x40 executing program [ 20.305595] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 20.306182] [ 20.306335] Freed by task 3471: [ 20.306649] save_stack+0x43/0xd0 executing program executing program [ 20.306957] kasan_slab_free+0x71/0xc0 [ 20.307416] kfree+0xca/0x250 [ 20.307722] disk_release+0x327/0x410 [ 20.308108] device_release+0x7c/0x200 [ 20.308512] kobject_put+0x14c/0x240 [ 20.308867] put_disk+0x23/0x30 executing program [ 20.309161] __blkdev_get+0x6ed/0xf90 executing program executing program executing program [ 20.309764] blkdev_get+0x3a1/0xad0 [ 20.312444] blkdev_open+0x1c9/0x250 [ 20.312800] do_dentry_open+0x664/0xd40 executing program [ 20.313162] vfs_open+0x107/0x220 [ 20.313757] path_openat+0x1151/0x3520 executing program executing program [ 20.314186] do_filp_open+0x25b/0x3b0 [ 20.314769] do_sys_open+0x502/0x6d0 [ 20.315223] SyS_open+0x2d/0x40 executing program [ 20.315642] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 20.316289] executing program executing program [ 20.316476] The buggy address belongs to the object at ffff880039a6d300 executing program executing program executing program executing program [ 20.316476] which belongs to the cache kmalloc-2048 of size 2048 executing program [ 20.322163] The buggy address is located 1408 bytes inside of [ 20.322163] 2048-byte region [ffff880039a6d300, ffff880039a6db00) [ 20.323686] The buggy address belongs to the page: executing program executing program [ 20.324142] page:ffffea0000e69b00 count:1 mapcount:0 mapping:ffff880039a6c200 index:0x0 compound_mapcount: 0 executing program [ 20.325192] flags: 0x100000000008100(slab|head) [ 20.325710] raw: 0100000000008100 ffff880039a6c200 0000000000000000 0000000100000003 executing program [ 20.326431] raw: ffffea0000e39aa0 ffffea0000f52520 ffff88003e800c40 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program [ 20.327192] page dumped because: kasan: bad access detected [ 20.333329] [ 20.333513] Memory state around the buggy address: executing program [ 20.334160] ffff880039a6d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program [ 20.334994] ffff880039a6d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program [ 20.336049] >ffff880039a6d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.337043] ^ [ 20.337417] ffff880039a6d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program [ 20.338112] ffff880039a6d980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.339124] ================================================================== executing program [ 20.339880] Disabling lock debugging due to kernel taint executing program executing program executing program [ 20.340722] Kernel panic - not syncing: panic_on_warn set ... [ 20.340722] [ 20.341623] CPU: 3 PID: 3471 Comm: blkid Tainted: G B 4.14.0-rc5-next-20171018+ #8 [ 20.342671] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 executing program [ 20.343699] Call Trace: [ 20.344075] dump_stack+0x194/0x257 executing program executing program [ 20.344463] ? arch_local_irq_restore+0x53/0x53 [ 20.345148] ? kasan_end_report+0x32/0x50 [ 20.347415] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 20.348122] ? vsnprintf+0x1ed/0x1900 executing program executing program executing program executing program executing program [ 20.348500] ? disk_unblock_events+0x50/0x60 executing program [ 20.349446] panic+0x1e4/0x41c [ 20.349909] ? refcount_error_report+0x214/0x214 [ 20.350506] ? add_taint+0x1c/0x50 [ 20.350972] ? add_taint+0x1c/0x50 executing program executing program [ 20.351383] ? disk_unblock_events+0x51/0x60 [ 20.352156] kasan_end_report+0x50/0x50 [ 20.352776] kasan_report+0x144/0x340 [ 20.353365] __asan_report_load8_noabort+0x14/0x20 [ 20.354023] disk_unblock_events+0x51/0x60 [ 20.354683] __blkdev_get+0x78d/0xf90 [ 20.355170] ? __blkdev_put+0x7c0/0x7c0 [ 20.355712] blkdev_get+0x3a1/0xad0 executing program executing program executing program executing program executing program executing program executing program [ 20.356128] ? do_raw_spin_trylock+0x190/0x190 [ 20.356704] ? bd_link_disk_holder+0x8b0/0x8b0 [ 20.357317] ? __fsnotify_parent+0xb4/0x3a0 [ 20.357955] ? errseq_sample+0xee/0x140 executing program [ 20.358457] ? _copy_to_user+0xc0/0xc0 executing program [ 20.359012] ? _raw_spin_unlock+0x22/0x30 executing program [ 20.359468] blkdev_open+0x1c9/0x250 [ 20.360023] ? security_file_open+0x89/0x190 [ 20.360550] do_dentry_open+0x664/0xd40 executing program [ 20.361091] ? security_inode_permission+0xbb/0xf0 [ 20.361779] ? bd_acquire+0x2c0/0x2c0 [ 20.362162] vfs_open+0x107/0x220 [ 20.362752] path_openat+0x1151/0x3520 [ 20.363326] ? path_lookupat+0xba0/0xba0 [ 20.363854] ? lock_downgrade+0x990/0x990 [ 20.364305] ? do_sys_open+0x2e7/0x6d0 executing program executing program executing program executing program executing program [ 20.364715] ? do_raw_spin_trylock+0x190/0x190 [ 20.365280] ? find_held_lock+0x35/0x1d0 [ 20.366189] ? __lock_is_held+0xb6/0x140 [ 20.366796] ? _find_next_bit+0xee/0x120 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 20.367218] ? _raw_spin_unlock+0x22/0x30 [ 20.373559] ? __alloc_fd+0x29b/0x750 [ 20.373952] do_filp_open+0x25b/0x3b0 [ 20.374240] ? may_open_dev+0xe0/0xe0 [ 20.374492] ? mpi_resize+0x200/0x200 [ 20.374892] ? get_unused_fd_flags+0x121/0x190 [ 20.375357] ? getname_flags+0x256/0x580 [ 20.375791] do_sys_open+0x502/0x6d0 executing program executing program executing program [ 20.376176] ? do_sys_open+0x502/0x6d0 [ 20.376566] ? filp_open+0x70/0x70 executing program executing program [ 20.376911] ? entry_SYSCALL_64_fastpath+0x5/0xbe [ 20.377422] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 20.377797] SyS_open+0x2d/0x40 [ 20.378147] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 20.378495] RIP: 0033:0x7f99b68cd120 executing program executing program [ 20.378806] RSP: 002b:00007ffe876f0068 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 20.379464] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f99b68cd120 executing program executing program executing program [ 20.379991] RDX: 00007ffe876f1f45 RSI: 0000000000000000 RDI: 00007ffe876f1f45 [ 20.380730] RBP: 0000000000000082 R08: 0000000000000078 R09: 0000000000000000 [ 20.381439] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000013fb030 executing program executing program [ 20.382247] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 [ 20.383555] Dumping ftrace buffer: [ 20.383847] (ftrace buffer empty) [ 20.384128] Kernel Offset: disabled [ 20.384400] Rebooting in 86400 seconds..